1. Field of the Invention
The invention relates to a manufacturing method of a device and a planarization process. More particularly, the invention relates to a manufacturing method of a device having a supporting layer and a planarization process.
2. Description of Related Art
With continuous reduction of the device size, the exposure light resolution for photolithography is increased. As the depth of the exposure light is reduced, the requirement for the varying degree of altitude of a wafer surface has become rather strict. Hence, when the manufacturing process is reduced to deep sub-micron, the planarization of the wafer is accomplished by performing a chemical mechanical polishing (CMP) process or an etch back process. The CMP process or the etch back process, due to its anisotropic polishing properties, can be applied to planarization the profile of the wafer surface, fabrication of vertical or horizontal metal interconnect in damascene structures, fabrication of shallow trench isolation (STI) devices and fabrication of advance devices in the first manufacturing stage, planarization of micro-electromechanical systems, fabrication of flat panel displays, and so on.
In general, when the CMP process and the etch back process are performed on the device having the undulated surface, a supporting layer is formed on the device. Openings formed on the undulated surface of the device are filled with the supporting layer, and a planarization process is performed on the supporting layer and the device, such that the device can have a planar surface. The remaining supporting layer is then removed. Here, the gap-fill capacity of the supporting layer poses an impact on the effects of the planarization process. Besides, the removal of the supporting layer complicates the planarization process.